The Administrative Core (Core A) of the competing continuation of the MIDUS POl is responsible for oversight and management of data collection, processing and documentation for all MIDUS samples and projects that comprise the proposed research. The Administrative Core takes lead responsibility in assuring quality control of MIDUS data and materials. The amount of data to be accurately accounted for across the multiple samples and five projects is considerable, with management of related tasks relying heavily on state of the art information and computing technology. There are four primary aims of Core A: (1) Administrative Oversight of Investigator Collaboration and Financial Matters. Successful achievement of the many aims in the proposed project depends on effective administrative management, including facilitating effective and productive communication among investigators as well as providing competent budgetary and personnel oversight. Our experience in the prior POl will inform the next proposed MIDUS initiatives. (2) Coordination of Data Collection. Newly recruited MIDUS respondents will be invited to participate in multiple aspects of the POl, making it critical to manage the sequencing of data collection efforts across the projects, and related communication with respondents. An Access Administrative Database will be used to coordinate these activities. Longitudinal follow-up ofthe existing sample also requires extensive coordination of tracking information with the UW Survey Center, (3) Management of Data Quality. The Administrative Core will oversee the production of high quality datasets that are the product of best practices in data cleaning, coding, and quality control. A critical feature of quality oversight is making sure that data are welldocumented and user-friendly, such that new users can easily gain a working understanding of the data set. Central to our documentation efforts is an Internet-based standard called the Data Documentation Initiative (DDI). (4) Management of Data Dissemination. The Administrative Core will deliver data from the newly recruited Refresher sample and the MIDUS III sample (survey and cognitive assessments) and related materials to the Inter-University Consortium for Political and Social Research (ICPSR) for public access and archiving. We will also provide timely summaries of MIDUS results to professional audiences and the general public via print and web-based media. Speaking to the competence of the Administrative Core personnel to carry out these tasks is our success in implementing and completing the complex data collection for MIDUS II. We have demonstrated effectiveness in carrying out all ofthe above objectives.